The Java Embedding Plugin is a utility that allows other web
browsers than Apple's Safari to use the most recent versions of Java
on Mac OS X. When used together with an updated version of Mozilla's
MRJ Plugin Carbon (included in this distribution), the Java Embedding
Plugin's functionality is currently available to recent versions of
Firefox, Seamonkey and Camino. But in principle any web browser could
use one of the Java Embedding Plugin's two APIs to add support for
Java 1.4.2, J2SE 5.0 and (where available) Java SE 6.

The current version (0.9.7.5) of the Java Embedding Plugin and the
MRJ Plugin JEP requires Mac OS X 10.4.X or higher. Older versions
(0.9.6.5 and earlier) required Mac OS X 10.2.8 or higher.

The Java Embedding Plugin has for the last few years been bundled
with current Mac distributions of all the Mozilla.org browsers --
Firefox, Seamonkey and Camino. So if you're using one of these
browsers, you don't need to install the Java Embedding Plugin. But
you may wish to replace the bundled version of the Java Embedding
Plugin with a more recent version.